British intelligence forces, MI5 and MI6, say they have identified the Islamic State fighter from the UK suspected of killing US journalist James Foley, according to top government sources, The Sunday Times reported.

The masked man,
nicknamed “Jihadi John” spoke with a London accent when
he appeared in chilling footage showing him murdering Foley, and
then threatening a second captive, American journalist Steven
Sotloff.

The Islamic State militant group released the footage last
Tuesday. Foley, a US freelance journalist, was captured by
militants in Syria in 2012, while Sotloff was kidnapped there in
2013.

Key suspect in the case is currently 23-year-old Abdel-Majed
Abdel Bary, according to The Sunday Times. Bary reportedly left
his family’s home in West London last year and has recently
posted a photo of himself holding a severed head.

Foreign Secretary Philip Hammond commented in The Sunday Times,
writing “it is horrifying to think that the perpetrator of
this heinous act could have been brought up in Britain.”

However, talking to CNN, Britain’s ambassador to the United
States, Peter Westmacott only said the country was “close” to
identifying the man.

"We're putting a lot into it," he said on Sunday, adding
the means included voice-recognition technologies.

Foreign Secretary Hammond also said the killing showcases not
only the threat of Islamism in Iraq and Syria, but signaled
“a barbaric ideology threatening us at home.”

Echoing him, Westmacott stated in his interview that the problem
"goes beyond one horrendous criminal."

"People think maybe as many as 500 British subjects have gone
to Syria and Iraq for this cause of jihad," he said.

There is rising concern in Britain about the threat from Islamic
extremism. Last year an off duty soldier, Lee Rigby, was killed
on a street in a London suburb by two British Muslim converts.

In July 2005, 52 people were killed by suicide bomb attacks on
London underground trains and buses carried out by four British
Muslims, two of whom had been to Al-Qaeda training camps in
Pakistan.

On Saturday, the UK home secretary, Theresa May, pledged to
strengthen laws to deal with British Islamic militants traveling
to the Middle East to fight for the Islamic State. New laws
dubbed “ASBO for terrorists” could be introduced for
those who radicalize others, while groups believed to encourage
terrorism could be banned.